Materials information on a file Blender Internal Render
A Text Editor window containing a Python Script.  Filename indicated has the suffix [.py].  Line numbers and Syntax Coloring enabled. Yellow arrows from left to right show, Window Type, Name of file, Buttons for line numbers and syntax coloring, Button to Run Script.  Image Above.

Only copy the newest software code sample.  The images above have older software.  But they address questions that may apply to you which are not letter by letter code specific.

NEWER

import bpy
import datetime

print("-" * 88)
print(datetime.datetime.now())
print("-" * 88)

def inspect_m_textures(simple_sleek):
    print(bpy.types.ImageTexture, " Preferred")
    for m in bpy.data.materials:
        #print("M ", m.name)
        b = False;
        for ts in m.texture_slots:
            if hasattr(ts, 'name'):
                b = True
                continue
        if b:
            print("M ", m.name)
            inspect_t_textures(simple_sleek, m.texture_slots)


def inspect_t_textures(simple_sleek, slots):
    #print(bpy.types.ImageTexture, " Preferred")
    n = 0
    fs = "%03d" # format string
    #for t in bpy.data.textures:
    for ts in slots:
        #print(t.name)
        #print(type(t))
        #n += 1
        if not hasattr(ts, 'name'):
            continue
        t = ts.texture
        if isinstance(t, bpy.types.ImageTexture) and hasattr(t,'image'):
            n += 1
            ns = fs % (n,)
            if hasattr(t,'image'):
                x = t.image
                if hasattr(x,'filepath'):
                    print(ns, t.name, t.image.name,t.image.filepath)
                else:
                    print(ns, t.name, "Incomplete", "Incomplete")
            else:
                print(ns, t.name, "No Image")
        elif not simple_sleek:
            n += 1
            ns = fs % (n,)
            print(ns, t.name, type(t), "Other No Match")



inspect_m_textures(True)    


OLDER

import bpy
import datetime

print("-" * 88)
    print(datetime.datetime.now())
print("-" * 88)

def inspect_textures():
    for t in bpy.data.textures:
        print(t.name)
        #print(type(t))
        if isinstance(t, bpy.types.ImageTexture) and hasattr(t,'image'):
            x = t.image
            if hasattr(x,'filepath'):
                print(t.name, type(t),t.image.filepath)
        else:
             print(t.name, type(t), "?")



inspect_textures()    


Python for Cut and Paste.  Code Block Above.  Inspect, Verify and Improve. You can delete comments and extra print statements and extra print arguments.

Open or use text editor window. New Text. Name Textures.py  . Copy and paste the text above.  Make sure the formatting is retained.  Execute from Button or Keystroke indicated on Tooltip of Button. The console window has the textual results. Toggle the visibility of the Console Window from the menu.  In the [Info] window Menu/Window/Toggle System Console



Console Window on Windows 10.  Console allows Copy and Paste.  Python allows Standard Out Redirection.  Image Above.



Toggle the System Console. Image above.